Most amphibians found in Europe inhabit ponds, small aquatic ecosystems commonly threatened by habitat degradation and destruction. Despite this situation, ponds are rarely considered in conservation policies. Thus, their effective management may present a significant opportunity to alleviate the ongoing decline of amphibian populations. In this study, we assessed if the favourable condition of a pond and its conservation stat...

Ponds and “pondscapes” (networks of ponds) are crucial habitats for biodiversity and for delivering multiple benefits to humans, so-called “Nature’s Contribution to People”, such as climate mitigation and adaptation to climate change, creation, and maintenance of habitat for biodiversity, water purification, flood mitigation and cultural benefits (e.g., recreational possibilities). However, ponds are not often considered as Na...

This study tested for links among behaviour, state and life‐history variables as predicted by the pace‐of‐life hypothesis in adult pike Esox lucius. First, a standardized open‐field behavioural assay was developed to assess individual behaviour of wild‐captured adult E. lucius . Behaviour within the standardized assay predicted swimming behaviour in the lake, providing an ecological validation of the assay. There was no relati...

Enhancement stocking is a widespread but rarely evaluated practice in German vendace, Coregonus albula L. fisheries, which is precautionarily carried out to buffer yield fluctuations. However, it is assumed that stocking of larval vendace can elevate year‐class strength only in the presence of substantial reproductive deficits, which so far cannot be detected prior to the spring time period when stocking is conducted by fisher...

This study examines a natural, rapid, fivefold increase in dissolved organic carbon (DOC) concentrations in a temperate shallow lake, describing the processes by which increased DOC resulted in anoxic conditions and altered existing carbon cycling pathways. High precipitation for two consecutive years led to rising water levels and the flooding of adjacent degraded peatlands. Leaching from the flooded soils provided an initial...

Lake ecosystems are strongly linked to their terrestrial surroundings by material and energy fluxes across ecosystem boundaries. However, the contribution of terrestrial particulate organic carbon (tPOC) from annual leaf fall to lake food webs has not yet been adequately traced and quantified. In this study, we conducted whole‐lake experiments to trace artificially added tPOC through the food webs of two shallow lakes of simil...

Morphological differentiation and microhabitat segregation of two ecologically similar populations of pelagic planktivorous fishes, Coregonus albula and the smaller Coregonus fontanae , were studied in Lake Stechlin (northern Germany). Both populations performed diel vertical migrations, although C. fontanae was always situated in deeper pelagic water than C. albula both during day and night. Landmark‐based geometric morphomet...

In this study gillnet catches of large roach Rutilus rutilus and their potential predators, large perch Perca fluviatilis , pikeperch Sander lucioperca and pike Esox lucius , in combination with data on food resources and abiotic variables were used to reveal the variables influencing the habitat use of large roach in Lake Großer Vätersee. The occurrence of large roach was negatively coupled with the occurrence of potential pr...

Mortality of small (60–100 mm total length) perch Perca fluviatilis after marking with coded wire tags in relation to water temperature (6·9, 14·2, 17·8 and 22·6° C) was experimentally tested and exclusively occurred within the first day of the experiments. Moreover, mortality rates were generally low with a maximum of 4%. No increased mortality at higher water temperatures was observed.

Morphotypes for 67 lakes in the German lowlands were derived, based on maximum depth and mixis type. A threshold of 11 m maximum depth was identified to be the best level to discriminate shallow from deep lake morphotypes. The fish communities in these two morphotypes were significantly different. Indicator species analyses based on fish biomasses found vendace Coregonus albula in deep lakes and ruffe Gymnocephalus cernuus , b...

Combined analyses of mitochondrial DNA (mtDNA) and microsatellite loci were performed to assess the genetic differentiation of two spring‐spawning ciscoes from each other and from sympatric Coregonus albula in two German lakes. Polymorphism was screened at six microsatellite loci and mtDNA for a total of 247 and 94 ciscoes, respectively. Microsatellite data showed a weak differentiation between spring‐spawning Coregonus fontan...

Biomanipulation, the reduction of planktivorous fish to enhance filter‐feeding zooplankton, has been used to rehabilitate eutrophied lakes. However, efficacy and long‐term success were dependent on nutrient load, lake morphometry and biomanipulation measures. The ongoing focus on sustainable use of aquatic resources offers the chance to perform lake rehabilitation using a combined strategy of nutrient load reduction and tradit...

A carp angler survey indicated that specialised carp anglers used on average 215 kg groundbaits (mostly cereals, nuts, beans, boilies) per year which corresponded to a mean annual gross P‐input of 1018 g P angler −1 . A feeding experiment was conducted with juvenile carp fed with a random sample of the main bait types used in coarse angling to estimate the nutritional quality and P‐retention efficiency. The investigated ground...

Monthly (April to November) hydroacoustic surveys and parallel gillnet catches were used to determine vendace Coregonus albula abundance, biomass and population dynamics in a deep oligotrophic lake. By hydroacoustic surveys, recruitment of 0+ year vendace could clearly be detected. In contrast, gillnet catches resulted in low numbers of 0+ year fish, and similarly under‐represented proportions of the oldest vendace. Consequent...

Juvenile roach Rutilus rutilus fed on the cyanobacterium Aphanizomenon were able to maintain liver glycogen and muscle protein concentrations. In contrast, internal energy stores of fish fed on the cyanobacterium Microcystis were degraded. Liver glycogen, however, was higher than in starved fish, suggesting that roach was able to obtain some nutrients (probably carbohydrates) from the mucus cover of Microcystis . Weak assimila...

Since bioenergetics models for 0+ fish have seldom been validated by field consumption estimates, field‐based and indirectly estimated daily food rations were compared in larval perch Perca fluviatilis and zander Stizostedion lucioperca. Field‐based estimates were calculated with linear and exponential evacuation rates based on gut fullness data during a 24‐h cycle, with hourly field samplings instead of the normally recommend...

Temperature and food availability are two important factors which affect fish growth and therefore are expected to influence habitat choice in fish. In this study, shoals of 16 juvenile roach, Rutilus rutilus , were given a choice between two chambers that differed in temperature by 1·5°C or 3°C whereas food availability was the same in both chambers (ratio 1 : 1) or higher in the colder one (ratio 4 : 1). The number of fish i...